Facile Synthesis of Fluorine Doped Graphitic Carbon Nitride with Enhanced Visible Light Photocatalytic Activity

NANO ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. 1650137 ◽  
Author(s):  
Mengqiu Xu ◽  
Bo Chai ◽  
Juntao Yan ◽  
Haibo Wang ◽  
Zhandong Ren ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Separation Efficiency ◽  
Nitrogen Adsorption ◽  
Active Species ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
X Ray

Fluorine doped graphitic carbon nitride (g-C3N4) was successfully synthesized by a convenient co-polycondensation of urea and ammonium fluoride (NH4F) mixtures, and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectra (FTIR), UV-Vis diffuse reflectance absorption spectra (UV-DRS), nitrogen adsorption–desorption, photoelectrochemical measurement and photoluminescence (PL) spectra. The photocatalytic activities of fluorine doped g-C3N4 samples were evaluated by the degradation of Rhodamine B (RhB) solution under visible light irradiation. The results showed that the fluorine doped g-C3N4 had a better photocatalytic activity than that of undoped g-C3N4, which was attributed to the favorable textural, optical and electronic properties derived from the fluorine atoms substituting nitrogen atoms of g-C3N4 frameworks. The photoelectrochemical measurements confirmed that the charges separation efficiency was improved by fluorine doping g-C3N4. Moreover, the tests of radical scavengers demonstrated that the holes (h[Formula: see text]) and superoxide radicals ([Formula: see text]O[Formula: see text]) were the main active species for the degradation of RhB.

scholarly journals Sugarcane juice derived carbon dot–graphitic carbon nitride composites for bisphenol A degradation under sunlight irradiation

2018 ◽  
Vol 9 ◽  
pp. 353-363 ◽  
Author(s):  
Lan Ching Sim ◽  
Jing Lin Wong ◽  
Chen Hong Hak ◽  
Jun Yan Tai ◽  
Kah Hon Leong ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Bisphenol A ◽  
Carbon Nitride ◽  
Separation Efficiency ◽  
Sugarcane Juice ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Dominant Factor ◽  
Spectroscopic Techniques ◽  
X Ray

Carbon dots (CDs) and graphitic carbon nitride (g-C3N4) composites (CD/g-C3N4) were successfully synthesized by a hydrothermal method using urea and sugarcane juice as starting materials. The chemical composition, morphological structure and optical properties of the composites and CDs were characterized using various spectroscopic techniques as well as transmission electron microscopy. X-ray photoelectron spectroscopy (XPS) results revealed new signals for carbonyl and carboxyl groups originating from the CDs in CD/g-C3N4 composites while X-ray diffraction (XRD) results showed distortion of the host matrix after incorporating CDs into g-C3N4. Both analyses signified the interaction between g-C3N4 and CDs. The photoluminescence (PL) analysis indicated that the presence of too many CDs will create trap states at the CD/g-C3N4 interface, decelerating the electron (e−) transport. However, the CD/g-C3N4(0.5) composite with the highest coverage of CDs still achieved the best bisphenol A (BPA) degradation rate at 3.87 times higher than that of g-C3N4. Hence, the charge separation efficiency should not be one of the main factors responsible for the enhancement of the photocatalytic activity of CD/g-C3N4. Instead, the light absorption capability was the dominant factor since the photoreactivity correlated well with the ultraviolet–visible diffuse reflectance spectra (UV–vis DRS) results. Although the CDs did not display upconversion photoluminescence (UCPL) properties, the π-conjugated CDs served as a photosensitizer (like organic dyes) to sensitize g-C3N4 and injected electrons to the conduction band (CB) of g-C3N4, resulting in the extended absorption spectrum from the visible to the near-infrared (NIR) region. This extended spectral absorption allows for the generation of more electrons for the enhancement of BPA degradation. It was determined that the reactive radical species responsible for the photocatalytic activity were the superoxide anion radical (O2 •−) and holes (h+) after performing multiple scavenging tests.

Cellulose nanofibrils anchored Ag on graphitic carbon nitride for efficient photocatalysis under visible light

2018 ◽  
Vol 5 (9) ◽  
pp. 2129-2143 ◽  
Author(s):  
Cuihua Tian ◽  
Xu Tao ◽  
Sha Luo ◽  
Yan Qing ◽  
Xihong Lu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Carbon Nitride ◽  
Cellulose Nanofibrils ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride

Cellulose nanofibrils were employed to anchor Ag onto a g-C3N4 framework to improve its photocatalytic activity remarkably under visible light.

scholarly journals Zirconia nanoparticle-modified graphitic carbon nitride nanosheets for effective photocatalytic degradation of 4-nitrophenol in water

2019 ◽  
Vol 9 (8) ◽  
Author(s):  
Mohanna Zarei ◽  
Jamil Bahrami ◽  
Mohammad Zarei
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Carbon Nitride ◽  
Diffuse Reflectance Spectroscopy ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zirconia Nanoparticle ◽  
Carbon Nitride Nanosheets

Abstract Zirconia (ZrO2)-modified graphitic carbon nitride (g-C3N4) nanocomposite was used for effective photodegradation of 4-nitrophenol (4-NP) in water. The ZrO2 nanoparticles, g-C3N4 nanosheets, and ZrO2/g-C3N4 nanocomposite were well characterized by including N2 adsorption, X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, UV–Vis diffuse reflectance spectroscopy, photoelectrochemical measurements, and photoluminescence spectroscopy methods. ZrO2/g-C3N4 nanocomposites were formed at room temperature using sonication and used for effective for photodegradation of 4-NP under irradiation with visible light. The nanocomposite samples resulted in a significant increase in photocatalytic activity compared with single-component samples of g-C3N4. In particular, the ZrO2/g-C3N4 nanocomposite exhibited the significant increase in the photocatalytic activity. The ZrO2/g-C3N4 nanocomposite showed an excellent catalytic activity toward the reduction of 4-NP in aqueous medium. Further, ZrO2/g-C3N4 nanocomposite can be reused several times for photocatalytic degradation as well as for 4-NP adsorption.

Preparation of Nitrogen-Deficient Graphitic Carbon Nitride with a Large Specific Surface Area by Melt Pretreatment and Its Photocatalytic Performance

NANO ◽  
2020 ◽  
Vol 15 (06) ◽  
pp. 2050079
Author(s):  
Xuelei Li ◽  
Jinfeng Bai ◽  
Jiaqi Li ◽  
Chao Li ◽  
Junru Zhang ◽  
...  
Keyword(s):  
Visible Light ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Nitride ◽  
Mesoporous Structure ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Large Specific Surface Area ◽  
X Ray

In this study, nitrogen-deficient graphitic carbon nitride (M-LS-g-C3N4) with a mesoporous structure and a large specific surface area was obtained by calcination after melt pretreatment using urea as a precursor. X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption, X-ray photoelectron spectroscopy (XPS), UV-Vis, ESR and photoluminescence (PL) were used to characterize the structure, morphology and optical performance of the samples. The TEM results showed the formation of a mesoporous structure on the 0.1[Formula: see text]M-LS-g-C3N4 surface. The porous structure led to an increase in the specific surface area from 41.5[Formula: see text]m2/g to 124.3[Formula: see text]m2/g. The UV-Vis results showed that nitrogen vacancies generated during the modification process reduced the band gap of g-C3N4 and improved the visible light absorption. The PL spectra showed that the nitrogen defects promoted the separation of photogenerated electron–hole pairs. In the visible light degradation of methyl orange (MO), the reaction rate constant of 0.1[Formula: see text]M-LS-g-C3N4 reached 0.0086[Formula: see text][Formula: see text], which was 5.05 times that of pure g-C3N4. Superoxide radicals and photogenerated holes were found to be the main active species in the reaction system. This study provides an efficient, green and convenient means of preparing graphitic carbon nitride with a large specific surface area.

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